Apparatus and Method for Passive Phase Change Thermal Management

1. An apparatus comprising: a phase change material; a plurality of particles intermixed with the phase change material; and a thermally conductive body encapsulating the phase change material within a cavity, the cavity formed from a pair of substantially identical, symmetrical halves of the conductive body coupled together, the cavity including first and second cavity surfaces, the first cavity surface being disposed along an upper side of the cavity and including a cone shape and the second cavity surface being disposed along a lower side of the cavity and including a sloping surface, the first cavity surface being oppositely disposed from the second cavity surface, each of the first and second cavity surfaces being configured to enhance formation of convection currents within the cavity during operation of an integrated circuit die, the conductive body including an upper finned first external surface and a lower second external surface configured to thermally couple the conductive body to a surface of the integrated circuit die.

2. The apparatus of claim 1 , wherein the first cavity surface has the shape of a flat top cone.

3. The apparatus of claim 2 , wherein the conductive body is configured to center a low area of the flat top cone shaped cavity surface above a hot spot of the integrated circuit die.

4. The apparatus of claim 1 , wherein a low area of the cone shaped cavity surface includes a point, the conductive body being configured to center the point above a hot spot of the integrated circuit die.

5. The apparatus of claim 4 , wherein the phase change material comprises TH58.

6. An apparatus comprising: a phase change material; a plurality of particles intermixed with the phase change material; and a thermally conductive body encapsulating the phase change material and the plurality of particles within a cavity, the cavity formed from a pair of substantially identical, symmetrical halves of the conductive body coupled together, the cavity including first and second cavity surfaces, the first cavity surface being disposed along an upper side of the cavity and including a first sloping surface and the second cavity surface being disposed along a lower side of the cavity and including a second sloping surface, the first cavity surface being oppositely disposed from the second cavity surface, each of the first and second cavity surfaces being configured to enhance formation of convection currents within the cavity during operation of an integrated circuit die, the conductive body including an upper finned first external surface and a lower second external surface configured to thermally couple the conductive body to a surface of the integrated circuit die.

7. The apparatus of claim 6 , wherein the phase change material includes TH58.

8. The apparatus of claim 7 , wherein at least some of the plurality of particles have an approximately spherical shape.

9. An integrated circuit heat sink, comprising: a thermally conductive body having a pair of substantially symmetrical halves forming a cavity, the cavity including first and second cavity surfaces each sloping upwardly from a low area located near a center of the cavity surface toward a side wall surface, the positioning of the first and second cavity surfaces being configured to enhance formation of convection currents within the cavity during operation of an integrated circuit die to which the body is coupled, the first cavity surface being disposed along an upper side of the cavity and the second cavity surface being disposed along a lower side of the cavity, the first cavity surface being oppositely disposed from the second cavity surface, the thermally conductive body including as finned first external surface and a second external surface configured to thermally couple the body to the integrated circuit die; and a mixture encapsulated within the cavity, the mixture including a phase change material and a number of particles.

10. The integrated circuit heat sink of claim 9 , wherein the first cavity surface has the shape of a cone.

11. The integrated circuit heat sink of claim 10 , wherein the first cavity surface has the shape of a flat top cone.

12. The integrated circuit heat sink of claim 11 , wherein the conductive body is configured to center the low area of the flat top cone shaped first cavity surface above a hot spot of the integrated circuit die.

13. The integrated circuit heat sink of claim 10 , wherein the low area of the cone shaped first cavity surface includes a point, the conductive body being configured to center the point above a hot spot of the integrated circuit die.

14. The integrated circuit heat sink of claim 9 , wherein the phase change material comprises TH58.

15. An integrated circuit heat sink, comprising: a pair of substantially symmetrical halves of a thermal conductive body, each of the pair of symmetrical halves coupled to form an enclosed cavity, the cavity including first and second sloping cavity surfaces each sloping upwardly from a low area located near a center of the sloping cavity surface toward a side wall surface, the first cavity surface being disposed along an upper side of the cavity and the second cavity surface being disposed along a lower side of the cavity, the first cavity surface being oppositely disposed from the second cavity surface; fins formed on a first, upper external surface of each of the pair of symmetrical halves; and a mixture encapsulated within the cavity, the mixture including a phase change material and a number of particles, wherein the conductive body includes a second, lower external surface configured to thermally couple the conductive body to a surface of an integrated circuit die.

16. The integrated circuit heat sink of claim 15 , wherein the fins are fused on the first external surface of each of the pair of symmetrical halves.

17. The integrated circuit heat sink of claim 15 , wherein most of the number of particles has an approximately spherical shape.